Technical Field
The instant disclosure relates to earphones, and more particular to a piezoelectric ceramic dual-frequency earphone structure having a dynamic transducer and a composite piezoelectric sheet.
Related Art
Most parity price earphone are classified as dynamic earphone in which a winded cylinder coil in a permanent magnetic field is connected with a vibrating diaphragm, and the coil is driven by currents to actuate the vibration of the vibrating diaphragm for the sound generation. Generally, a conventional dynamic earphone includes a housing, a vibrating diaphragm, a permanent magnet, a magnet conductive member, a fastening member and a voice coil. when sound are sent to the voice coil through an acoustic transmitting cable of the dynamic earphone, the voice coil generates an inductive magnetic field because of the electromagnetic effect, so that the inductive magnetic field interacts with the magnetic force generated by the magnet conductive member so as to push the vibrating diaphragm to vibrate, and the vibration of the medium is then converted into sound for output.
The conventional dynamic earphone has a single vibrating diaphragm for generating high and low sound simultaneously. The advantages of the conventional are lower cost and wider resolute frequency bands. While, one of the drawbacks of the conventional is, the single vibrating diaphragm is disable to separate the sound according to the frequencies, resulting in the deficiency for performing the sound resolution, the response positions and spatial resolutions clearly, especially for the high frequency bands. While an earphone utilizing low frequency voice coil along with high frequency voice coil is market available, the earphone has one vibrating diaphragm and failed to perform clear sound resolution.